EP0143454B1

EP0143454B1 - Gas actuated pistol

Info

Publication number: EP0143454B1
Application number: EP84114246A
Authority: EP
Inventors: Ilan Shalev
Original assignee: Israel Military Industries Ltd
Current assignee: Israel Military Industries Ltd
Priority date: 1983-11-28
Filing date: 1984-11-26
Publication date: 1989-03-08
Also published as: FI82311C; FI844446L; FI82311B; DE3477053D1; FI844446A0; IL73522A; EP0143454A3; EP0143454A2; IL73522A0

Description

The present invention relates to firearms and, more particularly, to pistols of the kind in which the gas generated during the firing of a bullet is used to actuate means for ejecting the spent case from the breech and for causing the firing hammer to be recocked. With such pistols it is also conventional for the pistol to be so designed that after said ejection of the spent casing and recocking of the firing hammer a fresh cartridge is extracted from a pistol magazine and inserted into the breech end of the pistol barrel.
A number of such pistols are already known in which the gas that expands in the barrel of the pistol on firing of a bullet is used to cause a slide to move rearwardly to cause automatic or semiautomatic operation of the aforesaid components.
Among such firearms are the pistols disclosed in U.S.-A-3,306,168 which has been selected as the nearest prior art for dividing the accompanying Claim 1 into a two-part form. In this prior art, and having regard in particular to Figs. 15 to 31 thereof, there is provided a pistol in which a gun barrel is threaded externally at its rear end and is screwed into a threaded bore of a main frame unit defining the handle of the pistol with its trigger, magazine, firing hammer and so on. Beneath the gun barrel is a breech slide and bolt assembly that can be forced rearwardly against spring means by the gas pressure generated in the gun barrel on the firing of a bullet. To this end the barrel of the pistol is formed with a bore close to the muzzle end of the pistol and this bore leads to a passageway below the barrel in which there is a plunger facing rearwardly of the pistol. With this pistol the bullet first travels the length of the barrel and then, just before it exits from the barrel, it crosses the aforesaid bore to then permit the pressurised gas in the barrel to pass via said bore to the passageway below the pistol and so thrust the plunger therein rearwardly of the pistol in a manner forcing the breech slide and bolt assembly rearwardly against its spring biassing means.
A somewhat similar pistol is disclosed in US-A-3,273,460 wherein the barrel of the pistol is formed with a plurality of bores near its muzzle end and these bores lead to a surrounding chamber whereby, once the bullet has passed these bores, the pressure of the firing gases in the barrel are used to move a part of the pistol rearwardly to actuate a mechanism for unlocking the breech block and for forcibly ejecting the spent cartridge.
In US-A-3,657,960 a further pistol is disclosed in which, again, the muzzle end of the barrel is provided with a bore by means of which, just before the bullet exits from the barrel, the pressurised gases in the barrel are placed in communication with means for operating the bolt-actuating system of the firearm.
FR-A-1,266,597 represents background art. These known pistols which utilize expanding gas, i.e. gas actuated firearms, include many parts and thus are complicated, difficult to take apart and reassemble, for cleaning or repairing. They are also quite expensive. In addition they are not believed to provide sufficiently high accuracy and reliability. Furthermore they are not designed nor capable of use with reassembling large caliber ammunition such as 0.357 or 0.440 ammo. Further, they do not make a maximum use of the gases generated on the firing or a bullet as will be clear from the description that follows.
All of the known disadvantages of the prior art gas operated pistols are believed to be overcome by the novel pistol of the present invention as defined in the accompanying claims. Broadly, the pistol of the present invention includes the features defined in claim 1. Prefered embodiments are defined in defendent claims.
The invention will best be understood from the following description when read in conjunction with the accompanying drawings.

Fig. 1 is a side view of the novel pistol;
Fig. 2 is an expanded isometric view of a major part thereof;
Fig. 3 is a cross-sectional view of the novel barrel;
Figs. 4 and 5 are partial views useful in explaining significant features of the invention;
Fig. 6 is a combination side cross-sectional view of the pistol;
Fig. 7 is a side view of a novel bolt; and
Fig. 8 is a combination cross-sectional block view of a novel hammer unit.

Attention is first directed to Figs. 1-4 in connection with which the novel gas actuated pistol of the present invention will first be described. The pistol 10 is made up of three basic major units or parts. They include a frame unit or simply frame A, a barrel unit or simply barrel B and a slidable unit or simply slide C. It further includes other parts which will be described in detail. The latter, whether forming an integral part of one of the major units or attached or supportable thereon, will generally be designated by a numeral followed by the letter of the unit, with which it is associated, as a suffix. As will become apparent from the following description of the pistol 10, its frame A, slide C and barrel B are easily assembled and disassembled for maintenance or repair. In Fig. 1 the pistol is shown fully assembled. The figure represents a side view of the pistol with its front or fore end through which a bullet or slug exists designated by 10f and its rear or aft end by 10r.
The fore and aft ends of each of frame A, barrel B and slide C are designated by the numerals 11 and 12, respectively, followed by the units designation letter, e.g. 11A and 12A, 11B and 12B and 11C and 12C. In Fig. 1 the pistol 10 is shown with slide C in its fore position.
As shown in Fig. 2, the frame A is designated as having a barrel-accommodating section 13A, a trigger section 14A and a hammer unit- accommodating section 15A. Section 13A is trough or U-shaped in cross-section and is formed by the vertical spaced apart side walls 16A which are joined together by a base 17A (see Fig. 1). Elongated grooves 19A are formed in the side walls 16A for facilitating the locking of the aft end 12B of the barrel B to frame A. As shown, the barrel unit B has an axial bore 15B extending from the barrel's fore end 11B which represents the bore's muzzle end, to aft end 12B, representing the bore's breech end. Barrel B further includes front and rear barrel locking members 19B and 20B at the fore end 11B and proximate aft end 12B, respectively. It is by means of these members that barrel B is releasably lockable to frame A through slide C. As will be described hereafter in detail in connection with Fig. 3, barrel B defines a unique path for gases produced at the bore's breech end through the barrel and through front locking member 19B, which provides the novel pistol with some of its unique advantages.
The front locking member 19B can be viewed of as a block which represents the fore section of the pistol with a front side or face representing fore end 11 B and an opposite side 22B against which the fore end 11 C of the slice C is biased, as will be described. Member 19B is uniquely shaped in that it defines two symmetrical cavities 21B which extend inwardly from side 22B. They are shaped and spaced apart to accommodate therein the fore ends of side walls 16A of frame A, while the fore end of the bottom 17A of the frame side is accommodated in a recess under side 22B (see Fig. 1). Thus, when the barrel B is locked to frame A, the front or fore end 11A of the frame is accommodated in front locking member B. The latter effectively is wrapped around the frame fore end 11A, thereby enhancing the fore interlocking of the two units for enhanced pistol performance.
In addition to cavities 21 B in member 19B, an axial cavity 25B is formed therein (see Figs. 2 and 3). The cavity extends inwardly from face 22B. The purpose of this cavity may best be explained in connection with Figs. 2-5. Fig. 3 is essentially a partial cross-sectional view of barrel B. As shown therein, in addition to bore 15B formed therein, a cavity or path 30B is formed. It extends from the breech end 12B, then below and along the bore 15B but spaced therefrom and up to the bottom end of cavity 25B. As is known, when a bullet is fired the burned propellants produce gases at high pressure. In the present invention these gases are made to travel along path 30B and exit through cavity 25B. It is the pressure of these gases which is used to push the slide C aft against a bias force provided by an arrangement which will be described.
Briefly, in section 13A of frame A a spring biasing assembly is located as shown in Fig. 4. It is located in the U-shaped trough of section 13A. It consists of two rods 25A on which springs 26A are wound. The aft ends of rods 25A are in appropriate grooves in wall 30A of the frame A while their other ends are supported on a horizontal plate 32A which is slidable on the rods.
Attention is now directed to Figs. 1 and 5. Fig. 5 is an end view of slide C on frame A. As shown, the fore end of 11C of slide C is shaped with a bridge-like member 15C which forms a bridge between side walls 13C of the slide. The top of the bridge member 15C is curved to accommodate the barrel B thereon. Extending from member 15C is a cylindrical post 20C. It is this post or piston which is accommodated in cavity 25B of the front locking member 19B. In addition, extending downwardly from bridge member 15C below piston 20C is a protrusion-like member or short bar 22C. It is bar 22C which presses against horizontal plate 22A. The bar does not extend over the entire width of the bridge as viewed in the fore to aft direction.
The slide C has appropriate grooves 25C shaped in its opposite sides 13C (see Fig. 1) to facilitate the insertion of rear locking member 20B of barrel B into frame A. The locking member 20b is inserted through grooves 25C in the slide and grooves 19A in the frame when the grooves are aligned and thereafter the front locking member 19B is positioned to accommodate the fore ends of sides 16A into openings 21B. Then the rear locking member 20B is locked in position with its aft side pressing against wall 30A and its fore side engaging a locking cam which is operable by turning a lever 35A (see Fig. 1). It should be appreciated that different arrangements may be employed to insert the aft end 12 of barrel B through slide C and lock it therein.
In the assembled position, as shown in Fig. 1, the barrel B is locked to the frame A. As to the slide C, it is biased fore by springs 26A pushing the plate 32A fore. It pushes arm 22C (Fig. 5) fore and thus urges the slide C forward. In the assembled position the fore end 11C of the slide abuts the rearwall 22B of the front locking member 19B, and the piston 20C is inside axial cavity 25B. In this position the slide C is biased fore by the springs 26A.
When a bullet is fired gases are created by the burning propellants at the breech end 12B of barrel B. Due to the high gas pressure the bullet or slug is propelled out of the bore. In accordance with the present invention, as shown in Fig. 3 and as previously explained, gas path 30B is provided in the barrel. This path starts at the breech end whereat the gas pressure is very high and ends in axial cavity 25B. Thus high pressure is produced thereat. Since piston 20C of the slide C is present in the cavity, it is subjected to the high pressure and as a result it is pushed axially out of the cavity 25B in the aft direction. Since the piston 20C is part of the bridge member 15C which in turn is part of the slide C, the entire slide C is pushed aft against the bias forces of the springs which urge it forward.
By using the pressure of the gases at the breech end to drive the axial slide back, very improved performance is attained.
As the slide C travels aft, the spent case in the breech end is extracted and the hammer 50A is cocked. Once the gas force is less than that applied by the springs, the slide C moves fore, during which a new cartridge is extracted from the magazine and is inserted into the breach end. Finally, the slide C returns to its most fore position and the pistol with the cocked hammer is ready to be fired again.
Attention is now directed to Fig. 6 which is a combination side view of the fore section of frame A and an isometric view of the aft section. Therein the hammer 50A is shown in the cocked position below a safety grip. As will be pointed out hereafter the hammer forms part of an easily removable hammer unit 55A. The entire hammer unit is held in position by two pins 56A and 57A which can be removed to repair or replace the hammer unit. Pin 57A is generally covered by a cover or held grip on the frame of the pistol handle in which a magazine is typically inserted. Numeral 59A designates the magazine latch.
As shown in Fig. 6 a sear lever 80 extends from the hammer unit. It is essentially hook-shaped. Its function is to engage a trigger bar 82 which is in turn controlled by the pistol trigger 60A.
The cocking of the hammer pulls the sear level aft. It in turn pulls the trigger bar 82 aft and the trigger is pulled forward. By pressing the trigger the trigger bar 82 is pulled forward, pulling with it the sear lever. When pulled forward sufficiently the spring holding the cocked hammer is released and the hammer is driven to strike the firing pin (not shown).
As shown in Fig. 6, the trigger bar 82 has a pair of ears 85 (one being shown). When the safety catch 65C (see Fig. 1) is turned to the safety position, inside slide C a cam presses on these ears 85. As a result, the trigger bar 82 is pressed down, clearing the sear lever 80. Thus, pressing on the trigger causes the trigger bar to move without engaging the sear lever.
As shown in Fig. 2, at the breech end 12B of bore B locking lugs are shown. They are designed to cooperate with the locking lugs of a bolt 35C in slide C. That is, the pistol is of the locking type. Since the slide C moves axially with respect to barrel B the bolt 35C, in addition to moving axially with the slide has to rotate somewhat to enable its locking lugs to interact with those of the barrel B. .The bolt is typically in the shape of an elongated cylinder with the lugs at one end thereof. Herebefore the bolt has been shaped with a cavity having a compound helical shape and extending through the-center of the bolt. A pin is fixedly positioned in a direction transverse to the bolt central axis. Although such an arrangement operates satisfactorily the bolt is undesirably weakened. In accordance with the present invention as shown in Fig. 7, a bolt 35C is provided which has a cavity 37C extending inwardly from the bolt's periphery. The cavity is shaped so that as the bolt 35C moves axially against a stationary pin a rotational motion is imparted to the bolt. By forming cavity 37C from the bolt periphery the bolt is much more reliable and has a much longer lifetime than prior art rotational bolts. The novel bolt can be thought of as a bolt with a peripherally extending cavity to impart to it a rotary motion as it moves linearly by a stationary pin, engaged in the cavity.
As previously pointed out the trigger unit can be easily removed. In accordance with another aspect of the present invention an adjustable two- stage trigger unit is provided. Both length and pressure of the trigger pull can be adjusted to suit the needs of the individual marksman. Such a unit is shown in Fig. 8. Therein numerals 101-104 respectively, designate the unit housing, the spring for hammer, a hammer spring support, and a member forming part of the sear lever, which can pivot about 105. Numeral 106 designates a spring which is used to control the trigger pull pressure, while 107 designates a pin about which spring 106 is wound. Numeral 108 designates a nut-like element against which one end of spring 106 presses, while 109 designates a pressure adjustment bolt. Numeral 110 designates the unit housing, while 112 designates a safety cover. An assembly pin 113 is also shown. The hammer post is designated by 115 and its pivot by 116. Finally, a trigger length control bar is shown as 117 and a trigger length bolt adjuster by 118.
As seen, the heads of bolts 109 and 118 are accessible from the outside. By turning bolt 109 farther in more pressure of trigger pull is required to pull the sear lever to the right (as shown). As to trigger length it is controlled by bolt 118. When bolt 118 is turned in and contact is formed between its tip and the sear lever element, the contact point being designated by 121, one length of the trigger pull is established. Otherwise a different length exists as a function of the contact point 122.

Claims

1. A fully gas operated pistol of the kind comprising a frame unit (A) defining first and second sections extending to the front and rear ends thereof;

a barrel unit (B) defining an axial bore (15B) with a muzzle end (11B) and a breech end (12B);

a bolt carrier slide unit (C) slidably supported on said frame unit (A) and biasing means (26A) having a first end in contact with said frame unit (A) and a second end in contact with the bolt carrier slide unit (C) for urging it forward;

a gas path (30B) in the barrel unit (B) permitting expanding gas resulting from the firing of a bullet to act against the bolt carrier slide unit (C) in a mannerforcing it, against the action of said biasing means (26A), from a forward position to a retracted position; and after the emergence of the bullet from the muzzle end (11B) permitting the bolt carrier slide unit (C) to be urged by said biasing means (26A) back into said forward positions;
characterized in that:

the barrel unit (B) has front and rear locking means (19B, 20B) adapted to be fixedly received by said frame unit (A) at the front and rear ends thereof;

the bolt carrier slide unit (C) is adapted to slide between said front and rear locking means (19B, 20B);

the bolt carrier slide unit (C) has a forward, barrel receiving bridge-like member (15C) connecting two opposite walls of the bolt carrier slide unit (C);

said second end of the biasing means (26A) acts aginst the bridge-like member (156);

a piston (20C) extends forwardly from said bridge-like member (15C),

said barrel unit (B) has near its muzzle end (11 B) a rearward facing cavity (25B) acting as a piston accommodating cavity for said piston (20C) of the bolt carrier unit (C);

the aforesaid gas path (30B) links the breech end (12B) of said axial bore (15B) directly with said piston accommodating cavity (25B) independently of the bore (15B) such that it is the gases at the breech end (12B) of the barrel unit (B) that are used to force the bolt carrier slide unit (C) to move rearwardly.

2. A fully gas operated pistol according to claim 1, characterized in that said front locking means (19B) of said barrel assembly (B) further include recesses (21 B) therein for accommodating therein at least two vertical side walls (16A) of the front end of said frame unit.

3. A fully gas operated piston according to claim 1 or 2, characterized in that biasing means (26A) comprises a pair of spaced apart springs disposed around spring guides (25A), and disposed beneath said barrel.

4. A fully gas operated pistol according to claim 3, characterized in that said biasing means (26A) further comprises a bar element (32A) slidable on said spring guides and said bridge-like means (15C) includes a tongue-like element whereby as force is applied to said piston to cause the bolt carrier unit to slide aft, said tongue-like element (22C) pushes said bar element (32A) aft on said spring guides (25A) thereby compressing the spaced apart springs.

5. A fully gas operated pistol according to claim 4, characterized in that said springs (26A) are coil-shaped, each being formed of a plurality of stranded wires.

6. In a gas operated pistol according to claim 1, an arrangement being characterized by trigger means including a trigger (60A) adapted to be pressed by a pistol user pivotably supported on said frame unit (A) and bar means (117) connected to an upper part of said trigger (60A) in said frame unit, and integral hammer means (50A) couplable to said frame as a single unit and including a hammer cockable away from an end of a pin, a sear element (104) locatable proximate to said bar means (117) and movable thereby so as to enable said hammer (50A) to be driven and strike the pin end, and adjustable control means (109, 118) integrally associated in said unit with said hammer (50A) and said bar means (117) for controlling the extent said bar means are advancable as a function of pressing said trigger before said bar means engage said sear element, and for controlling the pressure needed to be exerted on said trigger to advance said bar means to pull said sear element and thereby release said hammer (50A) to strike said pin.